US20070156166A1

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Publication number: US20070156166A1
Application number: US11/716,281
Authority: US
Inventors: Show-Mean Wu; Herbert Radisch
Original assignee: Scimed Life Systems Inc
Current assignee: Boston Scientific Scimed Inc
Priority date: 2003-02-13
Filing date: 2007-03-09
Publication date: 2007-07-05
Also published as: US20040162575A1; US7879005B2; US7285109B2

Abstract

A device for collapsing a balloon in the vasculature of a patient after an angioplasty procedure includes a balloon and at least one elastomeric member that is attached to the inner surface of the balloon at a plurality of attachment points. Preferably, the elastomeric member is an annular band that will stretch during balloon inflation. Consequently, when the balloon is deflated, the elastomeric member pulls on the balloon at its attachment points to return the balloon to a predetermined configuration, wherein the balloon collapses inwardly onto itself for subsequent removal of the balloon from the vessel.

Description

FIELD OF THE INVENTION

The present invention pertains generally to balloon devices which are used in interventional medical procedures. More particularly, the present invention pertains to angioplasty balloon devices which collapse a balloon during deflation for subsequent removal from the vasculature of a patient. The present invention particularly, though not exclusively, pertains to elastomeric members which are incorporated to collapse the balloon in a uniform and predictable manner during a balloon deflation.

BACKGROUND OF THE INVENTION

Many modern surgical techniques have been developed which are employed to alleviate or obviate the stenoses that are formed when plaque builds up in a patient's vessels. For example, several balloon angioplasty devices have been proposed for insertion into a vessel to compress the stenosis and widen the passageway through the vessel. In several respects, balloon angioplasty devices afford numerous advantages over alternative methods. Foremost among these advantages is that open-heart bypass surgery can often be avoided by using angioplasty surgical techniques to relieve stenoses in the vessels that supply blood to the heart. For obvious reasons, it is preferable to avoid open heart surgery whenever possible, because such surgery, as is well known, is invasive and can consequently require significant post-operative recovery time. Accordingly, rather than many alternative procedures, it is often preferable to use relatively simpler angioplasty surgical procedures, when such procedures are feasible. Importantly, angioplasty procedures can be performed in the peripheral vessels of a patient, as well as in the vessels that supply blood to the heart.

In an angioplasty surgical procedure, the balloon of a balloon catheter is initially in a deflated configuration as it is advanced through the vasculature into a vessel and positioned next to the stenosis that is to be treated. Once the balloon has been properly positioned, fluid is infused into the balloon to expand the balloon. As the balloon expands, it dilates the stenosis in the lumen of the vessel and compresses the plaque. This causes the plaque to break up or flatten out against the vessel wall. Once the stenosis has been compressed, however, the balloon needs to be deflated. In its deflated configuration, it is then either withdrawn from the vessel or placed across another stenosis, as necessary, to restore normal blood flow through the vessel.

During the deflation of a balloon, after an angioplasty procedure and prior to its removal from the vessel, it is desirable that the balloon be deflated into a predictable configuration as evenly and as compactly as practicable to facilitate removal of the balloon through tortuous passageways of the vessel. Several polymers which are desirable for use in balloon angioplasty catheters, because of their strength, such as polyethylene terephthalate and polyethylene naphthalate, are well known for poor refold characteristics.

In light of the above, it is an object of the present invention to provide a device that is useful for collapsing a balloon into a compact pleated cross-sectional configuration during balloon deflation to facilitate removal of the balloon from a patient's body. Another object of the present invention is to provide a device that is useful for collapsing a balloon in a uniform and predictable manner during balloon deflation. Yet another object of the present invention is to provide a device which is relatively simple to manufacture, easy to use, and comparatively cost effective.

SUMMARY OF THE INVENTION

The present invention is a device for predictably collapsing a balloon into a desired reconfiguration during its deflation. For the present invention, the device includes the balloon and at least one elastomeric member that is attached to the inside surface of the balloon at predetermined attachment points. The balloon, defining a longitudinal axis, can be any angioplasty balloon known in the art. The device is particularly effective, however, in construction with balloon materials which, due to their polymeric structure, resist heat setting and exhibit poor refold.

As contemplated for the present invention, it is preferable that a plurality of elastomeric members be attached to the inner surface of the balloon to influence deflation of the balloon. In particular, each elastomeric member is a generally annular-shaped band having an unstretched diameter, D_m. Further, each elastomeric band is attached to the inner surface of the balloon at a plurality of attachment points and is centered on the axis of the balloon. For example, each elastomeric member can be attached to the inner surface of the balloon at multiple separate attachment points by any means well known in the art, such as by gluing, bonding with anaerobic adhesive, heat bonding and laser welding.

When more than one elastomeric members are used for the present invention, the individual elastomeric members can be positioned at predetermined distances along the axis of the balloon. The consequence of this is that the attachments points of each elastomeric member are positioned in respective planes that are perpendicular to the axis of the balloon and substantially parallel to each other. Thus, corresponding attachment points on respective elastomeric members are spaced apart from each other. Preferably, these attachment points are aligned with each other and located at predetermined distances from each other in an axial direction. The predetermined distance between each elastomeric, member may vary depending upon the particular need. Also, the attachment points need not be axially aligned and, instead, can be helically aligned along the length of the balloon axis.

In operation, the initially deflated balloon is positioned in a vessel of the patient and is then infused with fluid to perform an angioplasty procedure. In this surgical procedure, the inflating balloon may pull on the unstressed elastomeric members at the respective attachment points. During balloon inflation, the elastomeric members may stretch and expand away from the axis. Because of the elastic nature of the elastomeric members, however, each elastomeric member is biased in its stressed configuration to return to its unstressed configuration. Thus, once the fluid begins to be removed from the balloon, the elastomeric members may pull on the balloon at their respective attachment points. Since corresponding attachment points on respective elastomeric members are axially aligned with each other, this pulling action on the balloon at these corresponding attachment points may create fold lines in the axial direction. As a result, the deflating balloon may fold onto itself along the axis to form a pleated cross-sectional shape. Once the balloon is deflated and the elastomeric members have returned to their unstressed, substantially ring-shaped form, the balloon catheter may then be removed from the vessel.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which:

FIG. 1 is a perspective view of the present invention, shown positioned in the vasculature of a patient, with the balloon in its deflated configuration;

FIG. 2A is a perspective view of the present invention, when the balloon is inflated, and the elastomeric members, shown in phantom, are in their stressed configurations;

FIG. 2B is a perspective view of the present invention, when the balloon is deflated, and the elastomeric members, shown in phantom, are in their unstressed configurations;

FIG. 3A is a cross-sectional view of the elastomeric member attached to the balloon as seen along thelines3A-3A inFIG. 2A; and

FIG. 3B is a cross-section view of the elastomeric member attached to the balloon, with the balloon in its deflated configuration as would be seen along thelines3B-3B inFIG. 2B.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring initially toFIG. 1, an angioplasty balloon in accordance with this present invention is shown and is generally designated10. Theballoon10 is shown inserted into avessel12 of apatient14 and positioned adjacent to astenosis16 in thevessel12. As is also shown,balloon10 is connected in fluid communication with ahollow catheter tube18 which, in turn, is connected in fluid communication with afluid source20. If required, theballoon10, along with thecatheter tube18, can be inserted into thepatient14 through aninsertion catheter22. Theballoon10 is preferably made of any suitable angioplasty balloon material, such as polyethylene terephthalate or polyethylene naphthalate.

The present invention can perhaps be best appreciated by cross-referencingFIGS. 2A and 2B. In contrast to each other,FIG. 2A showselastomeric members24a-ein their stressed configurations, withballoon10 inflated.FIG. 2B, on the other hand, showselastomeric members24a-ein their unstressed configuration, withballoon10 deflated. As shown inFIGS. 2A and 2B, theelastomeric members24a-eare attached to aninner surface23 of theballoon10. In detail, theballoon10 has amidsection25 defining alongitudinal axis26 and

end portions

27aand27bthat are attached to themidsection25. Whenballoon10 is inflated (FIG. 2A), themidsection25 of theballoon10 is substantially cylindrical-shaped and the ends27a-bare substantially conical-shaped. Specifically, when inflated, the ends27a-bhave adiameter28 that decreases in a direction away from themidsection25.FIGS. 2A and 2B show theballoon10 with fiveelastomeric members24a-eattached to theinner surface23 of theballoon10. In particular, two respectiveelastomeric members24d-eare shown in the corresponding conical-shaped end portions27a-b. It is to be appreciated that these fiveelastomeric members24a-eare only exemplary, for there may be either fewer or moreelastomeric members24 attached to theballoon10 as desired.

As shown inFIGS. 2A and 2B, eachelastomeric member24a-e, is positioned around theaxis26, and is attached to theinner surface23 of theballoon10 at a plurality of attachment points30a-d. As shown, eachelastomeric member24a-eis attached to theinner surface23 of theballoon10 at four attachment points30a-d, by any means well known in the art. These four attachment points30a-d, however, are only exemplary. It would be appreciated that eachelastomeric member24 may be attached to theinner surface23 of theballoon10 at either fewer or more attachment points30 as desired. It can also be appreciated that the attachments could be made asymmetrically or from an asymmetric folded balloon shape, if desired. In any case, these attachment points30a-dbetween one of theelastomeric members24 and theballoon10 can perhaps be best seen inFIGS. 3A and 3B.

As shown inFIGS. 3A and 3B, theelastomeric member24 is attached to theinner surface23 of theballoon10 at four attachment points30a-d. With four attachment points30a-d, each attachment point30 is azimuthally distanced from adjacent attachment points30 by approximately ninety degrees (90°).FIG. 3A shows an azimuthal angle, β, between attachment points30cand30dthat is approximately ninety degrees (90°). On the other hand, when anelastomeric member24 is attached to theballoon10 at three attachment points30 (not shown), each attachment point30 is azimuthally distanced from adjacent attachment points30 by approximately one hundred twenty degrees (120°).

Referring back toFIGS. 2A and 2B, eachelastomeric member24a-eis shown attached to theballoon10 at its respective attachment points30a-d. In order for theelastomeric members24a-eto act in concert to collapse theballoon10 during balloon deflation, it is preferable that corresponding attachment points30a-don respectiveelastomeric members24a-e, as shown inFIG. 2A, are spaced apart from each other and are axially aligned at a predetermined linear distance32a-din the axial direction, as shown inFIG. 2B. For the present invention, these predetermined distances32a-dbetweenelastomeric members24a-emay vary depending upon the particular need.

For the present invention, eachelastomeric member24 will move between a stressed configuration, as shown inFIGS. 2A and 3A, and an unstressed configuration, as shown inFIGS. 2B and 3B, depending on whetherballoon10 is inflated or deflated. Specifically, whenballoon10 is inflated, and when theelastomeric members24a-eare in their stressed configurations (FIGS. 2A and 3A),balloon10 will pull on theelastomeric members24a-eat their respective attachment points30a-d. As a result, when attached at four attachment points30a-d, eachelastomeric member24 expands and assumes a substantially square or rectangular shape. This can be seen inFIGS. 2A and 3A. Theinflated balloon10 has a substantially circular cross-sectional shape with a diameter34 (D_b), as shown inFIG. 3A. Furthermore, when theballoon10 is inflated, the diameter34 (D_b) of theinflated balloon10, as shown inFIG. 3A, is greater than the diameter36 (D_m) of the unstressedelastomeric member24, as shown inFIG. 3B. More specifically, thediameter34 of theinflated balloon10 is approximately eight to twelve times greater than thediameter36 of theelastomeric member24 in its unstressed configuration. For example, thediameter34 of theinflated balloon10 can be ten times greater than thediameter36 of the elastomeric member24 (D_b=10D_m).

Whenballoon10 is deflated, and theelastomeric members24a-ereturn to their unstressed configurations (FIGS. 2B and 3B), eachelastomeric member24 may be substantially ring-shaped and may have anunstretched diameter36, D_m, as shown inFIG. 3B. Eachelastomeric member24 may pull on theballoon10 at its respective attachment points30a-dto return theelastomeric member24 to its unstressed configuration. Further, when theelastomeric members24a-epull at their respective attachment points30a-d, theballoon10 may fold over at the attachment points30a-dand collapse onto itself. As a result, theballoon10, in its deflated configuration, has a pleated cross-sectional shape, as shown inFIG. 3B.

Since corresponding attachment points30a-dare axially aligned with each other, as shown inFIG. 2A, as theelastomeric members24a-epull theballoon10 toward theaxis26, theballoon10 may fold at fold lines38 created by the axially aligned attachment points30. (The fold lines38aand38bshown inFIGS. 2A and 2B are only exemplary.) As shown, these fold lines38 are, preferably, oriented substantially parallel to theaxis26. Alternatively, the fold lines38 could have a helical orientation in relation to theaxis26. In either case, these fold lines38 assist theballoon10 in predictably collapsing onto theaxis26, and into a desired reconfiguration after deflation.

Operation

In the operation of the present invention,balloon10 is first in a deflated configuration, as shown inFIG. 2B. As shown, when theballoon10 is deflated, theelastomeric members24a-eare in their unstressed configurations.Deflated balloon10 can then be inserted through theinsertion catheter22 and advanced into the patient14 until theballoon10 is positioned adjacent thestenosis16, as seen inFIG. 1. Fluid fromfluid source20 can then be infused intoballoon10 throughcatheter tube18 to inflate theballoon10 in accordance with appropriate angioplasty procedures.

Balloon

10, when it is infused with fluid fromfluid source20, presses against thestenosis16 to expand the lumen of thepatient14. Meanwhile, as theballoon10 is being inflated, theelastomeric members24a-eare being pulled by the inflatingballoon10 at their respective attachment points30a-d. Consequently, eachelastomeric member24 moves from its unstressed configuration to its stressed configuration. In more detail, eachelastomeric member24 expands away to assume a substantially square or rectangular shape, when attached to theballoon10 at four attachment points30a-d.

In the stressed configuration, eachelastomeric member24 is biased toward its unstressed configuration to collapse theballoon10 inwardly towardaxis26. Accordingly, when fluid is withdrawn fromballoon10, eachelastomeric member24 pulls theballoon10 at its respective attachment points30a-dto returnballoon10 to its deflated configuration, as shown inFIGS. 2B and 3B. In more detail, since corresponding attachment points30a-don respectiveelastomeric members24a-eare axially aligned at predetermined distances32a-din the axial direction, theelastomeric members24a-epull at their respective attachment points30a-dand create fold lines38 on theballoon10 where theballoon10 folds over. The fold lines38 are initially created, in large part, as a result of the

elastomeric members

24dand24epulling on respective attachment points30a-din

respective end portions

27aand27b. As a result of theelastomeric members24a-epulling on the attachment points30a-d, theballoon10 will collapse at the fold lines38 onto itself and fold onto theaxis26. In its deflated configuration,balloon10 may be subsequently removed from thevessel12 of thepatient14.

Although the present invention has been described above in accordance with an angioplasty procedure performed in thevessel12 of apatient14, it will be appreciated that theballoon10 can be inserted into thevessel12 of the patient14 to perform a different surgical procedure. For example, theballoon10 can be inserted into an air passageway of the patient14 to widen the passageway. Accordingly, the present invention is intended to have universal application in surgical procedures performed on thepatient14.

While the particular Device and Method for Collapsing an Angioplasty Balloon as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.

Claims

1. A reconfiguration device which comprises:

an elongated balloon defining an axis and having an inner surface, said balloon being moveable between an inflated configuration wherein said balloon is substantially cylindrically shaped, and a deflated configuration wherein said balloon is collapsed onto said axis along predetermined fold lines in said balloon; and

at least one elastomeric member attached to a plurality of attachment points on said inner surface of said balloon to guide said balloon into said deflated configuration upon deflation of said balloon.

2. A device as recited inclaim 1 wherein said elastomeric member is attached to said inner surface of said balloon at four attachment points.

3. A device as recited inclaim 1 further comprising a plurality of said elastomeric members.

4. A device as recited inclaim 1 wherein said elastomeric member is ring-shaped in an unstressed state, and has a diameter, D_m, and said balloon in said inflated configuration has a diameter, D_b, wherein D_b>D_m.

5. A device as recited inclaim 1 wherein said balloon further comprises:

a midsection having a substantially cylindrical-shape in the inflated configuration, said midsection defining the axis;

a first end portion attached to said midsection, said first end portion surrounding the axis and having a substantially conical-shape in the inflated configuration with a diameter decreasing in a direction away from said midsection; and

a second end portion attached to said midsection, said second end portion surrounding the axis and having a substantially conical-shape in the inflated configuration with a diameter decreasing in a direction away from said midsection.

6. A device as recited inclaim 5 wherein said elastomeric member is a first elastomeric member and said plurality of attachment points is a first plurality of attachment points, with said first plurality of attachment points located on said inner surface of said balloon in said midsection, said device further comprising:

a second elastomeric member attached to a second plurality of attachment points on said inner surface of said balloon in said first end portion to guide said first end portion toward the axis to facilitate the collapse of said balloon along said fold lines upon deflation of said balloon; and

a third elastomeric member attached to a third plurality of attachment points on said inner surface of said balloon in said second end portion to guide said second end portion toward the axis to facilitate the collapse of said balloon along said fold lines upon deflation of said balloon.

7. A device as recited inclaim 1 wherein said balloon is made of polyethylene naphthalate.

8. A collapsible balloon which comprises:

an elongated, hollow body member defining a longitudinal axis and having an inner surface, said body member being moveable between an inflated configuration wherein said body member has a substantially circular cross-sectional shape and a deflated configuration wherein said body member has a pleated cross-sectional shape;

a plurality of predetermined fold lines formed in said body member wherein said body member is collapsed onto said axis along said fold lines to form said pleated cross-sectional shape;

a plurality of attachment points on said inner surface of said body; and

at least one elastomeric member attached to said plurality of attachment points on said body member to guide said balloon into said deflated configuration.

9. A balloon as recited inclaim 8 further comprising a plurality of elastomeric members.

10. A balloon as recited inclaim 9 wherein each said elastomeric member is attached to said inner surface of said body member at four respective attachment points.

11. A balloon as recited inclaim 10 wherein each said elastomeric member is ring-shaped in an unstressed state when said body member is in said deflated configuration, and further wherein each said elastomeric member is substantially square-shaped in a stressed state when said body member is in said inflated configuration.

12. A balloon as recited inclaim 11 wherein each said elastomeric member in said unstressed configuration has a diameter, D_m, and said body member in said inflated configuration has a diameter, D_b, and wherein D_bis in a range between 1.5D_mand 15D_m.

13. A balloon as recited inclaim 8 wherein said body member further comprises:

14. A balloon as recited inclaim 13 wherein said elastomeric member is a first elastomeric member and said plurality of attachment points is a first plurality of attachment points, with said first plurality of attachment points located on said inner surface of said body member in said midsection, said balloon further comprising:

a second elastomeric member attached to a second plurality of attachment points on said inner surface of said body member in said first end portion to guide said first end portion toward the axis to facilitate the collapse of said body member onto said axis along said fold lines; and

a third elastomeric member attached to a third plurality of attachment points on said inner surface of said body member in said second end portion to guide said second end portion toward the axis to facilitate the collapse of said body member onto said axis along said fold lines.

15. A device for collapsing a balloon from an inflated configuration to a deflated configuration, said balloon having an inner surface, and said device comprising:

a plurality of substantially ring-shaped elastomeric members;

a means for attaching each of said plurality of elastomeric members to said inner surface of said balloon at a respective plurality of attachment points; and

a means for moving said elastomeric member between a stressed configuration wherein said balloon is in said inflated configuration and an unstressed configuration wherein said balloon is in said deflated configuration to collapse said balloon.

16. A device as recited inclaim 15 wherein each said elastomeric member is attached to said inner surface of said balloon at respective three attachment points, and further wherein each said elastomeric member is substantially triangular-shaped in said stressed configuration wherein said balloon is in said inflated configuration, and said elastomeric member being biased in said stressed configuration to return said balloon to said deflated configuration.

17. A device as recited inclaim 15 wherein each said elastomeric member is attached to said inner surface of said balloon at respective four attachment points, and further wherein each said elastomeric member is substantially rectangular-shaped in said stressed configuration when said balloon is in said inflated configuration, and said elastomeric member being biased in said stressed configuration to return said balloon to said deflated configuration.

18. A device as recited inclaim 16 wherein each said elastomeric member in said unstressed configuration has a diameter, D_m, and said balloon in said inflated configuration has a diameter, D_b, wherein D_b>D_m.

19. A device as recited inclaim 18 wherein D_bis in a range between 1.5D_mand 15D_m.

20. A device as recited inclaim 15 wherein said balloon defines an axis and wherein said device further comprises a plurality of predetermined fold lines formed in said balloon along said axis for collapsing said balloon onto said axis when said plurality of elastomeric members move from said stressed configuration to said unstressed configuration.